The present invention is related to climate control systems for coach vehicles. More particularly, the present invention relates to climate control systems for school buses and buses used in local transit applications. Even more particularly, the invention relates to heating systems within such buses.
Buses, particularly school and transit buses, comprise a class of motor vehicle having unique requirements. Liability issues arise because they transport a large number of passengers. The economics of construction, maintenance, and operation of large fleetsxe2x80x94frequently by government agencies, such as school districts or transit authoritiesxe2x80x94is also a relevant factor.
More often than not, the budgets of state and local education departments are stretched to the limit; available assets, such as building space and school buses, must be used to their maximum potential. State and local school districts cannot afford to maintain a surplus of vehicles in their transportation fleets in order to cover for vehicles that are out of commission for any appreciable length of time. Vehicle down time should ideally be minimized so that a school bus can be repaired between its morning pickup and afternoon drop-off runs.
In particular, the climate control systems that heat and cool the passenger compartments of such vehicles are especially vexing. Such systems are subject to breakdown, due to the manner in which school buses and local transit coaches are used. Because such vehicles stop frequently to take on passengers, their heating or cooling units run almost continuously. The different components of the system thus may break down as a result of constant use. For example, blower motors within such units wear out or need replacement, and heating or cooling lines develop leaks.
Conventional climate control systemsxe2x80x94particularly heating systemsxe2x80x94for vehicles such as school buses have been located behind the dashboard and thus serviceable only from the interior of the passenger compartment. The dashboard and defrosting ducts typically have to be removed to gain access to the heating unit for repairs. The entire operation is complex and time consuming, requiring several hours to complete. The vehicle is effectively removed from fleet service for at least a day.
School and transit buses often have auxiliary heating units located underneath seats and near the side walls of the passenger compartment. These units may take in air through the exterior walls of the bus, but are still only serviceable from the interior of the bus.
The inaccessible climate control systems presently found in school buses do not permit easy repair and rapid turnaround. Therefore, what is needed is a climate control system for a school bus that does not require extensive disassembly for service or repair.
The present invention fulfills these needs in the art by providing a climate control system that is readily serviceable from outside the passenger compartment of a bus. In the present invention, a frame surrounds the components of a climate control unit, which may be either a heater or air conditioning unit. A climate control system having a heater is described in the preferred embodiment. The exterior wall may be situated on either the front, sides, or rear of the passenger compartment. The frame extends inwardly into the passenger compartment through an exterior wall of the compartment. The frame may be a simple structurexe2x80x94such as a rackxe2x80x94that holds and maintains the components of the climate control system in a proper relationship with each other. This embodiment of the frame is appropriate when the climate control system, when installed, is positioned between other components, such as a storage compartment or an audio system, such that neighboring components help direct the airflow through the climate control mechanism. In the absence of such neighboring components, the frame has walls and panels to perform this function.
In the preferred embodiment, the frame includes a casing that projects into the passenger compartment. The casing has a top wall, a floor, and three side walls. An air intake, through which fresh air is drawn from the exterior of the vehicle, is provided in one of the side walls or the floor. The location of the air intake depends on the location on the climate control system in the passenger compartmentxe2x80x94i.e., whether the system is located at the front, side, or rear of the compartment. In the preferred embodiment, the air intake is located in the floor of the casing. Similarly, an outlet through one of the casing walls is provided for the air that is either heated or cooled by the climate control unit. The outlet leads to a ducting system within the passenger compartment that distributes the air exiting the climate control system into the passenger compartment. In a preferred embodiment of the present invention, a seal is formed between the outlet of the casing wall and the duct in order to minimize leakage of exiting air from the system.
The climate control unit is serviceable from outside the passenger compartment through the cavity defined by the floor, top, and sides of the frame. A removable cover plate seals the cavity to protect the unit from the elements. The removable cover plate may be hingedly attached to either the frame or casing. In the preferred embodiment, the cover plate is affixed by attachment means such as screws or bolts to flanges formed in the side walls of the casing.
Preferably, the heater assembly includes an air filtering means, a heat exchanging means, and an air circulating means. The heater assembly is accessible from the exterior of the passenger compartment when the exterior cover plate is removed.
The present invention also provides a bus comprising: a chassis; a body that includes a passenger compartment attached the chassis; an internal combustion engine mounted on the chassis and having a liquid cooling system in which the liquid coolant within the cooling system is heated by the engine; a circulating system that circulates the heated liquid coolant from the cooling system around the body to distribute heated coolant along a path; a heater for the passenger compartment mounted on the body and operably linked to receive the distributed coolant, wherein the heater includes a heat exchanger and a blower that are mounted in the body and are accessible from the exterior of the body for repair or replacement.
The present invention also provides a maintenance method for a heater installed within a body of a bus comprising the steps of: removing a cover plate from an exterior surface of the body and exposing the heater components; servicing components of the heater; and re-installing the cover plate on the exterior of the surface of the body.